diff options
| -rw-r--r-- | src/drivers/elog/elog.c | 300 |
1 files changed, 207 insertions, 93 deletions
diff --git a/src/drivers/elog/elog.c b/src/drivers/elog/elog.c index 606f5e7954..f65c0d648b 100644 --- a/src/drivers/elog/elog.c +++ b/src/drivers/elog/elog.c @@ -41,6 +41,7 @@ #define elog_debug(STR...) #endif +#define NV_NEEDS_ERASE (~(size_t)0) /* * Static variables for ELOG state */ @@ -53,8 +54,13 @@ static elog_area_state area_state; static elog_header_state header_state; static elog_event_buffer_state event_buffer_state; -static u16 next_event_offset; -static u16 event_count; +/* + * The non-volatile storage chases the mirrored copy. When nv_last_write + * is less than the mirrored last write the non-volatile storage needs + * to be updated. + */ +static size_t mirror_last_write; +static size_t nv_last_write; static struct spi_flash *elog_spi; /* Device that mirrors the eventlog in memory. */ @@ -82,19 +88,89 @@ static size_t elog_events_total_space(void) return total_size - elog_events_start(); } -/* - * Pointer to an event log header in the event data area - */ static struct event_header *elog_get_event_buffer(size_t offset, size_t size) { return rdev_mmap(mirror_dev_get(), offset, size); } +static struct event_header *elog_get_next_event_buffer(size_t size) +{ + return elog_get_event_buffer(mirror_last_write, size); +} + static void elog_put_event_buffer(struct event_header *event) { rdev_munmap(mirror_dev_get(), event); } +static size_t elog_mirror_reset_last_write(void) +{ + /* Return previous write value. */ + size_t prev = mirror_last_write; + mirror_last_write = 0; + return prev; +} + +static void elog_mirror_increment_last_write(size_t size) +{ + mirror_last_write += size; +} + +static void elog_nv_reset_last_write(void) +{ + nv_last_write = 0; +} + +static void elog_nv_increment_last_write(size_t size) +{ + nv_last_write += size; +} + +static void elog_nv_needs_possible_erase(void) +{ + /* If last write is 0 it means it is already erased. */ + if (nv_last_write != 0) + nv_last_write = NV_NEEDS_ERASE; +} + +static bool elog_should_shrink(void) +{ + return mirror_last_write >= full_threshold; +} + +static bool elog_nv_needs_erase(void) +{ + return nv_last_write == NV_NEEDS_ERASE; +} + +static bool elog_nv_needs_update(void) +{ + return nv_last_write != mirror_last_write; +} + +static size_t elog_nv_region_to_update(size_t *offset) +{ + *offset = nv_last_write; + return mirror_last_write - nv_last_write; +} + +/* + * When parsing state from the NV one needs to adjust both the NV and mirror + * write state. Therefore, provide helper functions which adjust both + * at the same time. + */ +static void elog_tandem_reset_last_write(void) +{ + elog_mirror_reset_last_write(); + elog_nv_reset_last_write(); +} + +static void elog_tandem_increment_last_write(size_t size) +{ + elog_mirror_increment_last_write(size); + elog_nv_increment_last_write(size); +} + /* * Update the checksum at the last byte */ @@ -283,7 +359,6 @@ static void elog_flash_erase(void) */ static void elog_update_event_buffer_state(void) { - u32 count = 0; size_t offset = elog_events_start(); elog_debug("elog_update_event_buffer_state()\n"); @@ -314,17 +389,13 @@ static void elog_update_event_buffer_state(void) } /* Move to the next event */ - count++; + elog_tandem_increment_last_write(len); offset += len; } /* Ensure the remaining buffer is empty */ if (!elog_is_buffer_clear(offset)) event_buffer_state = ELOG_EVENT_BUFFER_CORRUPTED; - - /* Update ELOG state */ - event_count = count; - next_event_offset = offset; } static void elog_scan_flash(void) @@ -342,8 +413,8 @@ static void elog_scan_flash(void) elog_spi->read(elog_spi, flash_base, total_size, mirror_buffer); rdev_munmap(rdev, mirror_buffer); - next_event_offset = elog_events_start(); - event_count = 0; + /* No writes have been done yet. */ + elog_tandem_reset_last_write(); /* Check if the area is empty or not */ if (elog_is_buffer_clear(0)) { @@ -353,6 +424,9 @@ static void elog_scan_flash(void) area_state = ELOG_AREA_HAS_CONTENT; + /* Indicate that header possibly written. */ + elog_tandem_increment_last_write(elog_events_start()); + /* Validate the header */ if (!elog_is_header_valid()) { header_state = ELOG_HEADER_INVALID; @@ -363,7 +437,7 @@ static void elog_scan_flash(void) elog_update_event_buffer_state(); } -static size_t elog_write_header_in_mirror(void) +static void elog_write_header_in_mirror(void) { static const struct elog_header header = { .magic = ELOG_SIGNATURE, @@ -376,19 +450,7 @@ static size_t elog_write_header_in_mirror(void) }; rdev_writeat(mirror_dev_get(), &header, 0, sizeof(header)); - return sizeof(header); -} - -static void elog_prepare_empty(void) -{ - - elog_debug("elog_prepare_empty()\n"); - - /* Write out the header */ - size_t size = elog_write_header_in_mirror(); - elog_flash_write(0, size); - - elog_scan_flash(); + elog_mirror_increment_last_write(elog_events_start()); } static void elog_move_events_to_front(size_t offset, size_t size) @@ -425,16 +487,12 @@ static void elog_move_events_to_front(size_t offset, size_t size) rdev_munmap(rdev, dest); } -/* - * Shrink the log, deleting old entries and moving the - * remaining ones to the front of the log. - */ -static int elog_shrink(void) +/* Perform the shrink and move events returning the size of bytes shrunk. */ +static size_t elog_do_shrink(size_t requested_size, size_t last_write) { const struct region_device *rdev = mirror_dev_get(); size_t offset = elog_events_start(); - - elog_debug("elog_shrink()\n"); + size_t remaining_size; while (1) { const size_t type_offset = offsetof(struct event_header, type); @@ -444,7 +502,7 @@ static int elog_shrink(void) uint8_t len; /* Next event has exceeded constraints */ - if (offset > shrink_size) + if (offset > requested_size) break; if (rdev_readat(rdev, &type, offset + type_offset, size) < 0) @@ -460,24 +518,68 @@ static int elog_shrink(void) offset += len; } - elog_move_events_to_front(offset, next_event_offset - offset); + /* + * Move the events and update the last write. The last write before + * shrinking was captured prior to resetting the counter to determine + * actual size we're keeping. + */ + remaining_size = last_write - offset; + elog_move_events_to_front(offset, remaining_size); + elog_mirror_increment_last_write(remaining_size); + + /* Return the amount of data removed. */ + return offset - elog_events_start(); +} - elog_flash_erase(); - elog_flash_write(0, total_size); - elog_scan_flash(); +/* + * Shrink the log, deleting old entries and moving the + * remaining ones to the front of the log. + */ +static void elog_shrink_by_size(size_t requested_size) +{ + size_t shrunk_size; + size_t captured_last_write; + size_t total_event_space = elog_events_total_space(); - /* Ensure the area was successfully erased */ - if (next_event_offset >= full_threshold) { - printk(BIOS_ERR, "ELOG: Flash area was not erased!\n"); - return -1; - } + elog_debug("%s()\n", __func__); + + /* Indicate possible erase required. */ + elog_nv_needs_possible_erase(); + + /* Capture the last write to determine data size in buffer to shrink. */ + captured_last_write = elog_mirror_reset_last_write(); + + /* Prepare new header. */ + elog_write_header_in_mirror(); + + /* Determine if any actual shrinking is required. */ + if (requested_size >= total_event_space) + shrunk_size = total_event_space; + else + shrunk_size = elog_do_shrink(requested_size, + captured_last_write); /* Add clear event */ - elog_add_event_word(ELOG_TYPE_LOG_CLEAR, offset - elog_events_start()); + elog_add_event_word(ELOG_TYPE_LOG_CLEAR, shrunk_size); +} + +static int elog_prepare_empty(void) +{ + elog_debug("elog_prepare_empty()\n"); + elog_shrink_by_size(elog_events_total_space()); + + if (!elog_is_area_valid()) + return -1; return 0; } +static void elog_shrink(void) +{ + if (elog_should_shrink()) + elog_shrink_by_size(shrink_size); +} + #ifndef __SMM__ #if IS_ENABLED(CONFIG_ARCH_X86) @@ -549,17 +651,7 @@ int elog_clear(void) if (elog_init() < 0) return -1; - /* Erase flash area */ - elog_flash_erase(); - elog_prepare_empty(); - - if (!elog_is_area_valid()) - return -1; - - /* Log the clear event */ - elog_add_event_word(ELOG_TYPE_LOG_CLEAR, elog_events_total_space()); - - return 0; + return elog_prepare_empty(); } static void elog_find_flash(void) @@ -584,6 +676,48 @@ static void elog_find_flash(void) full_threshold); } +static int elog_sync_to_nv(void) +{ + size_t offset; + size_t size; + bool erase_needed; + + /* Determine if any updates are required. */ + if (!elog_nv_needs_update()) + return 0; + + erase_needed = elog_nv_needs_erase(); + + /* Erase if necessary. */ + if (erase_needed) { + elog_flash_erase(); + elog_nv_reset_last_write(); + } + + size = elog_nv_region_to_update(&offset); + + elog_flash_write(offset, size); + elog_nv_increment_last_write(size); + + /* + * If erase wasn't performed then don't rescan. Assume the appended + * write was successful. + */ + if (!erase_needed) + return 0; + + elog_scan_flash(); + + /* Mark broken if the scan failed after a sync. */ + if (!elog_is_area_valid()) { + printk(BIOS_ERR, "ELOG: Sync back from NV storage failed.\n"); + elog_initialized = ELOG_BROKEN; + return -1; + } + + return 0; +} + /* * Event log main entry point */ @@ -634,22 +768,19 @@ int elog_init(void) /* Load the log from flash */ elog_scan_flash(); - /* Prepare the flash if necessary */ - if (header_state == ELOG_HEADER_INVALID || - event_buffer_state == ELOG_EVENT_BUFFER_CORRUPTED) { - /* If the header is invalid or the events are corrupted, - * no events can be salvaged so erase the entire area. */ - printk(BIOS_ERR, "ELOG: flash area invalid\n"); - elog_flash_erase(); - elog_prepare_empty(); - } - - if (area_state == ELOG_AREA_EMPTY) - elog_prepare_empty(); + /* + * Mark as initialized to allow elog_init() to be called and deemed + * successful in the prepare/shrink path which adds events. + */ + elog_initialized = ELOG_INITIALIZED; + /* Prepare the flash if necessary */ if (!elog_is_area_valid()) { - printk(BIOS_ERR, "ELOG: Unable to prepare flash\n"); - return -1; + printk(BIOS_ERR, "ELOG: flash area invalid\n"); + if (elog_prepare_empty() < 0) { + printk(BIOS_ERR, "ELOG: Unable to prepare flash\n"); + return -1; + } } printk(BIOS_INFO, "ELOG: FLASH @0x%p [SPI 0x%08x]\n", @@ -658,18 +789,6 @@ int elog_init(void) printk(BIOS_INFO, "ELOG: area is %d bytes, full threshold %d," " shrink size %d\n", total_size, full_threshold, shrink_size); - elog_initialized = ELOG_INITIALIZED; - - /* Shrink the log if we are getting too full */ - if (next_event_offset >= full_threshold) - if (elog_shrink() < 0) - return -1; - - /* Log a clear event if necessary */ - if (event_count == 0) - elog_add_event_word(ELOG_TYPE_LOG_CLEAR, - elog_events_total_space()); - #if !defined(__SMM__) /* Log boot count event except in S3 resume */ #if CONFIG_ELOG_BOOT_COUNT == 1 @@ -689,8 +808,6 @@ int elog_init(void) #endif #endif - elog_initialized = ELOG_INITIALIZED; - return 0; } @@ -747,7 +864,7 @@ void elog_add_event_raw(u8 event_type, void *data, u8 data_size) } /* Make sure event data can fit */ - event = elog_get_event_buffer(next_event_offset, event_size); + event = elog_get_next_event_buffer(event_size); if (event == NULL) { printk(BIOS_ERR, "ELOG: Event(%X) does not fit\n", event_type); @@ -767,19 +884,16 @@ void elog_add_event_raw(u8 event_type, void *data, u8 data_size) elog_update_checksum(event, -(elog_checksum_event(event))); elog_put_event_buffer(event); - /* Update the ELOG state */ - event_count++; - - elog_flash_write(next_event_offset, event_size); - - next_event_offset += event_size; + elog_mirror_increment_last_write(event_size); printk(BIOS_INFO, "ELOG: Event(%X) added with size %d\n", event_type, event_size); /* Shrink the log if we are getting too full */ - if (next_event_offset >= full_threshold) - elog_shrink(); + elog_shrink(); + + /* Ensure the updates hit the non-volatile storage. */ + elog_sync_to_nv(); } void elog_add_event(u8 event_type) |